question about mrc 1666 sounder

[rustycoupler]

 my question is , if i replace the speaker on this to a smaller one can i use it in n scale in a b unit ? if i can what size soeaker should i use? thanks

[RDG1519]

Rustycoupler,

First I model in HO and I have no feel for what will fit into an N "B" unit, you can use a different speaker but it must be 8 ohm. The capacitor is built in on the "Sounder". Tony's has some small speakers that will work. It is in their "Dream Speakers" listing, a 1/2 inch is the smallest. This will need a baffel for good quality sound.

One issue I have with the "Sounder" is the volume is loud. I started a posting last week called "How to quiet down the MRC Sounder" and a lot of good advice came on it. This post should be required reading for using the "Sounder". Even when you set the volume down to the lowest settings it is like being "trackside". (exageration but you get my point).

Of the four sounds available on Model 1666 the "F" unit and the RS-3 are the best. SD 60 and SD 70 are high pitched, this may have been a volume issue for me. I will use the "Sounder" "F" in some of my P2K geeps and Stewart "F" units.

Hope this helps, Chris

[GC&P]

I've installed a number of MRC sound decoders - some of them Sounders, some the Brilliance series. All are too loud. I use a resistor in series with the speaker. Anything in the range of 47 ohms to 100 ohms seems about right to me. I've used half watt and one watt ratings. I think the amplifier is rated 1 watt and most of the power is dissipated in the resistor, so theorectically, the resistor should be 1 watt. But if you turn the volume down using the appropriate CV setting (which I do), then less power is being put out. Also, the power rating is into 8 ohms. When the load resistance is raised, the power should drop - unless the amp tries to compensate by raising the output voltage. I don't think this is happening, since given the available supply voltage, the amp would go into clipping if it tried to raise the output voltage very far. I'm not hearing this.

[mikebo]

I have replaced the speaker on a sounder 1662 with a 5/8" x 1.25" oval speaker with no significant change in sound. It maybe a little bit quieter but not much. I would think you can use any 8 ohm speaker and get ok results except that the bass will diminish with a small speaker. See how large a speaker will fit in your loco size to fit.